This disclosure relates the projection of patterns for liveness verification of biometrics.
Biometrics includes the study of methods for uniquely recognizing humans based upon one or more intrinsic physical or behavioral traits. Many biometric identification methods already exist for face recognition and for iris prints. Some systems even have liveness checks such as watching for eyeblinks in a face or for the pulsation of the pupil in an iris image. However, these methods do not try to recover the 3-dimensional geometry of the object that is being imaged.
The 3-dimensional geometry of an object, such as, for example, a human face may however be determined in a number of different ways. One method of doing so involves taking images of a human face with a pair of offset cameras and using the images to perform a stereo depth computation. This method has the advantage of being passive, i.e., no energy is emitted. However, it is expensive because of the use of two cameras. It is also expensive computationally.
It is therefore desirable to have an inexpensive method by which the 3-dimensional shape of a characteristic portion of a face or any other feature of the human body can be imaged and determined.